1. Field of the Invention
Embodiments of the invention generally relate to electronic devices and methods for forming electronic devices, and more particularly, in one embodiment, to memory devices and methods for forming memory devices.
2. Description of the Related Art
Flash memory has been widely used as non-volatile memory for a wide range of electronic applications, such as mobile phones, personal digital assistants (PDAs), digital cameras, MP3 players, USB devices, and the like. As flash memory is typically used for portable recording devices to store large amounts of information, a reduction in power consumption and cell sizes, along with increased operational speed, are very desirable.
A flash memory device 100, as depicted in FIG. 1, includes a floating gate electrode 102 for storing electrical charge. The floating gate electrode 102 is located on a tunnel oxide layer 104 which overlies a channel region 106 located between source and drain regions 108. Electrons are transferred to the floating gate electrode 102 through the tunnel dielectric layer 104 overlying the channel region 106. Electron transfer is generally initiated by either hot electron injection or Fowler-Nordheim tunneling. An overlying control gate electrode 110, which is capacitively coupled to the floating gate electrode 102, applies a voltage potential to the floating gate electrode 102. The floating gate electrode 102 is separated from the control gate electrode 110 by an inter-poly dielectric 112 which generally contains an oxide-nitride-oxide structure (“ONO”). However, as device dimensions are reduced and the corresponding thickness of the ONO structure is reduced leakage currents through the thinner ONO structure have increased.
Therefore there is a need for a device and methods for forming a device that allow for a reduction in device dimensions while also maintaining or reducing leakage current with high charge carrier mobility for electronic devices, such as memory devices.